Simplify the following expression: $k = \dfrac{8a}{2a - 6b} - \dfrac{6b - 12}{2a - 6b}$ You can assume $a,b,c \neq 0$.
Answer: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{8a - (6b - 12)}{2a - 6b}$ $k = \dfrac{8a - 6b + 12}{2a - 6b}$ The numerator and denominator have a common factor of $2$, so we can simplify $k = \dfrac{4a - 3b + 6}{a - 3b}$